Using soil sensors which detect the condition of a substrate on the basis of electromagnetic induction (EMI) is known from the state of the art in the field of geophysics. In this case, a primary field is generated by an electromagnetic transmitting coil, which induces an electromagnetic secondary field in the substrate as a function of the soil condition, which is recorded and evaluated by one or more receiving coils in the surface region.
Conductivity values are derived from the signals of the receiving coils, from which values, depending on the configuration and sensitivity of the coils, the condition of the substrate, for example the density, the water saturation and the soil type, can be determined at a depth of a few cm to several meters.
Since, in contrast to other geophysical methods, EMI technology can be used in almost all substrate situations and is also relatively inexpensive to purchase, it has become established as a measuring method in precision farming. The main field of application of established systems is to survey soil inhomogeneities laterally in their own measurement runs and then to make them available to the farmer in the form of maps and plans.
In some cases, motorized systems are used, which are mounted on a usually specially constructed hitch system and pulled over the examination surface. In this case, a large distance of the soil sensor to the towing vehicle must be maintained in order to prevent as much as possible quality-reducing measurement noise or other errors in the data collection.
In the operation of known soil sensors, the data collection takes place independently of farmer's cultivation runs, since the operation of the system and the evaluation of the data requires specialized personnel. A complex process, in which the farmer is not involved, thus runs from the data acquisition to the delivery of the maps with the evaluated soil data.
Conventional devices are known, for example, from US 2013/113648 A1, US 2014/0097831 A1, DE 20 2004 011 921 U1, U.S. Pat. No. 7,443,154 B1 and EP 1 241 488 A2.
A device and a method for the analysis and the mapping of soil and terrain are known from the cited EP 1 241 488 A2, wherein the sensor is arranged in a box trailer, which is trailed behind a motorized vehicle.